scholarly journals Counterfactual ghost imaging

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Jonte R. Hance ◽  
John Rarity
Keyword(s):  
Signal To Noise Ratio ◽  
Ghost Imaging ◽  
Signal To Noise ◽  
Interesting Phenomenon ◽  
Order Of Magnitude ◽  
Noise Ratio

AbstractWe give a protocol for ghost imaging in a way that is always counterfactual—while imaging an object, no light interacts with that object. This extends the idea of counterfactuality beyond communication, showing how this interesting phenomenon can be leveraged for metrology. Given, in the infinite limit, no photons ever go to the imaged object, it presents a method of imaging even the most light-sensitive of objects without damaging them. Even when not in the infinite limit, it still provides a many-fold improvement in visibility and signal-to-noise ratio over previous protocols, with over an order of magnitude reduction in absorbed intensity.

Effect of turbulence on visibility and signal-to-noise ratio of lensless ghost imaging with thermal light

Optik ◽  
2013 ◽  
Vol 124 (24) ◽  
pp. 6973-6977 ◽  
Author(s):  
Yin-Ping Yao ◽  
Ren-Gang Wan ◽  
Shi-Wei Zhang ◽  
Tong-Yi Zhang
Keyword(s):  
Signal To Noise Ratio ◽  
Ghost Imaging ◽  
Signal To Noise ◽  
Thermal Light ◽  
Noise Ratio

Proposal for a Laue lens with quasi-mosaic crystalline tiles

2011 ◽  
Vol 44 (6) ◽  
pp. 1255-1258 ◽  
Author(s):  
Vincenzo Guidi ◽  
Valerio Bellucci ◽  
Riccardo Camattari ◽  
Ilaria Neri
Keyword(s):  
High Resolution ◽  
Crystal Size ◽  
Signal To Noise Ratio ◽  
Signal To Noise ◽  
Laue Lens ◽  
Crystalline Anisotropy ◽  
Order Of Magnitude ◽  
Mosaic Crystals ◽  
Noise Ratio ◽  
Very High

Quasi-mosaicity is an effect of secondary bending within a crystal driven by crystalline anisotropy. This effect can be used to fabricate a series of curved crystals for the realization of a Laue lens. It is highlighted that crystals bent by the quasi-mosaic effect allow very high resolution focusing with respect to mosaic crystals. Under the same conditions for energy passband, crystal size and flux of incident photons, a Laue lens based on quasi-mosaic crystals would increase the signal-to-noise ratio by about an order of magnitude compared to the same lens with mosaic crystals. Moreover, no mosaic defocusing occurs for quasi-mosaic crystals.

scholarly journals Systematic analysis of signal-to-noise ratio in bipartite ghost imaging with classical and quantum light

2011 ◽  
Vol 83 (6) ◽  
Author(s):  
G. Brida ◽  
M. V. Chekhova ◽  
G. A. Fornaro ◽  
M. Genovese ◽  
E. D. Lopaeva ◽  
...  
Keyword(s):  
Signal To Noise Ratio ◽  
Ghost Imaging ◽  
Signal To Noise ◽  
Systematic Analysis ◽  
Noise Ratio

scholarly journals Signal transmission through the dark-adapted retina of the toad (Bufo marinus). Gain, convergence, and signal/noise.

1990 ◽  
Vol 95 (4) ◽  
pp. 717-732 ◽  
Author(s):  
D R Copenhagen ◽  
S Hemilä ◽  
T Reuter
Keyword(s):  
Ganglion Cells ◽  
Signal To Noise Ratio ◽  
Signal Transmission ◽  
Absolute Threshold ◽  
Spatial Summation ◽  
Bipolar Cells ◽  
Horizontal Cells ◽  
Signal To Noise ◽  
Order Of Magnitude ◽  
Noise Ratio

Responses to light were recorded from rods, horizontal cells, and ganglion cells in dark-adapted toad eyecups. Sensitivity was defined as response amplitude per isomerization per rod for dim flashes covering the excitatory receptive field centers. Both sensitivity and spatial summation were found to increase by one order of magnitude between rods and horizontal cells, and by two orders of magnitude between rods and ganglion cells. Recordings from two hyperpolarizing bipolar cells showed a 20 times response increase between rods and bipolars. At absolute threshold for ganglion cells (Copenhagen, D.R., K. Donner, and T. Reuter. 1987. J. Physiol. 393:667-680) the dim flashes produce 10-50-microV responses in the rods. The cumulative gain exhibited at each subsequent synaptic transfer from the rods to the ganglion cells serves to boost these small amplitude signals to the level required for initiation of action potentials in the ganglion cells. The convergence of rod signals through increasing spatial summation serves to decrease the variation of responses to dim flashes, thereby increasing the signal-to-noise ratio. Thus, at absolute threshold for ganglion cells, the convergence typically increases the maximal signal-to-noise ratio from 0.6 in rods to 4.6 in ganglion cells.

Amplitude and Frequency Dependence of the Signal-to-Noise Ratio in LDV Measurements

2011 ◽  
Author(s):  
Patrick F. O’Malley ◽  
Joseph F. Vignola ◽  
John A. Judge
Keyword(s):  
Vibration Amplitude ◽  
Signal To Noise Ratio ◽  
Speckle Pattern ◽  
Laser Doppler Vibrometer ◽  
Signal To Noise ◽  
Velocity Response ◽  
Order Of Magnitude ◽  
Noise Ratio ◽  
Ldv Measurement ◽  
The Relationship

When making measurements using many sensors, it is expected that, within normal operating ranges, the signal-to-noise ratio is approximately linear (i.e. 20 dB/decade). This generality does not hold, however, when making measurements using a laser Doppler vibrometer (LDV). If the velocity of the target of an LDV measurement increases by an order of magnitude, changes in the speckle pattern will introduce noise into the measurand. An experiment was conducted using an LDV system to measure the velocity response of a speaker excited over several orders of magnitude in both frequency and amplitude. Results are presented showing the relationship between signal-to-noise ratio and vibration amplitude.

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